[39] The best account of the quarrel, especially in its relation to the composition of the cabinet, is to be found in Walpole's _Life of Perceval_, vol. i., chap. ix., and vol. ii., chap. i. Lewis, _Administrations_, pp. 314-15, finds a double ground for Canning's resignation in his failure to obtain the removal of Castlereagh from the war office and in the refusal of the king and cabinet to allow him to succeed Portland as prime minister. It is quite clear, however, that at the time of Canning's resignation no decision had been come to about a successor to Portland. Some correspondence had passed between Canning and Perceval, in which each had refused to serve under the other, but that this correspondence was unknown to the cabinet as a whole is proved by Mulgrave's letters to Lord Lonsdale of September 11 and 15 (Phipps, _Memoir of Ward_, pp. 210-17); in the former of these he discusses Canning's probable conduct without referring to this correspondence, while in the latter he only knows of such negotiations as subsequent to the resignations of September 6 and 8. So, too, Eldon's letter to his wife of September 11 (Twiss, _Life of Eldon_, ii., 88-90), places the whole correspondence between Canning and Perceval after Portland's resignation on September 6. The king was not informed of Canning's views as to a successor to Portland till September 13, and the cabinet minute of September 18, advising co-operation with Grenville and Grey, mentions the selection of Canning as prime minister as a course open to the king. [40] This is the date commonly given. The _Annual Register_, li. (1809), 239, gives the 22nd, while Perceval refers to the result of the duel in a letter dated the 20th (Colchester, _Diary_, ii., 209). It is clear, however, that Canning did not receive Castlereagh's challenge till the morning of the 20th (see his letter in _Annual Register_, _loc. cit._, 505, also his detailed statement to Camden, _ibid._, 525), and therefore the duel cannot have taken place till the 21st. Lord Folkestone in a letter dated the 21st refers to the duel as having been fought at "7 o'clock this morning" (_Creevey Papers_, i., 96). CHAPTER IV. PERCEVAL AND LIVERPOOL.